High critical currents by isotropic magnetic-flux-pinning centres in a 3 µm-thick YBa₂Cu₃O₇superconducting coated conductor

Abstract

The critical current densities Jc−w(H) per unit width of the tape were measured at 75 K in applied magnetic fields H on a 3 µm-thick YBa2Cu3O7 film on a metallic substrate fabricated using the BaF2 process. Jc−w(H) was the highest reported for YBa2Cu3O7 conductors with H perpendicular to the tape, and was independent of the angle between H and the tape plane for μ0H≤3 T. The film did not contain artificial flux-pinning centres, implying the existence of a strong isotropic-pinning centre in undoped YBa2Cu3O7 films, thus opening up unexplored avenues for improving performance of coated conductors.